Transmission gearing



March 6, 1934. L, BANNAN 1,949,643

TRANSMISSION GEARING Filed Oct. 7, 1931 BYM (I ///5' ATTORNEY 6 3mm Q,I:

unit's Philip L. ldannaii, San Francisco, (Bahia, assis ants to PacificGear Tool Works, San Francisco, Salli, a corporation (California,

ll o ilicatieri @ctoher J, 19311, Na l (Claimed (CH. i l i inventionrelates to transmission Z, secured housing by means of the cap andparticularly to reduction ear units. screws 8, serves together with thewall 9 One of the objects of my invention is the pro flanges ll, tosupport the various shaft bearings. vision in a transmission, where thetorque from A driving; shaft 112, secured by means of a taper 5 thedrive shaft is transmitted to the driven shaft pin is seated in the endof the shaft by duplex intermediate gearing, of means for the primemover; and the connected shafts are equalizing the distribution oftorque between the journaled. in a hub 16, which forms part of theintermediate gearing so that each gear carries its wall 9. The drivingshaft gear 17 is a spiral share or the load. gear and is preferablyformed integrally with y Another object of my invention is the provisionthe shaft A, of means for quickly and accurately synchroniz A drivenshaft 18 is disposed in the housing. ing transmission gearingincorporating drive and preferably in axial alinement with the drivingdriven shafts connected by a plurality or hire shaft; and is journaledin a ball bearingl9, se= gear trains. cured by a retaining cap 21, in ahub 22, forming 2 5 Another object of my invention is the elimina partof :e cover plate F. A driven gear 23 is m 121011, to a large degree, ofthe extreme accuracy provided i 1 the shaft 18; and is preferably ah ofgear tooth registration heretofore practiced internal 1. .g whose teethare in parallelism in the construction oi transmission gear devices withthe driven she axis. The ring is including duplicategear secured bymeans of the lzey 242, for rotation gg Still another object of myinvention is the with the sha it. a.

provision of a transmission gear unit which does 1 the Outer ends of thdrivin d w 210i; require, 01 yeplage nenfi purposes, exact drivenShall)? 1S DYOVEC'LSOZ by ball hearings Zfi and matching of the part tbe replaced, 27 respectively, disposed in a hub 28 projecting; Theinvention possesses other objects and teafrom a Web 01 C O S member 29Secured y the 25 tires of advantage. some of which, with the bolts fi 110f the housing an.

foregoing, will he set forth in the following de A plurality, preferablytwo, of like intermediate scription of my invention. It is to beunderstood sea t each infiluding the helical driving that IE do notlimit myself to this disclosure of gear 17 and driven ring s ar isprovided sioeeies 1 m inventi n, as I may adopt, v iant for operativelyconnecting the driving and driven embodiments thereof within the scopeoi the shafts. Dispose a j 011 f l 35 time. opposite sides of, ar' inparallelism with re driv= Referring to the drawh'ig": ins driven. sh sare a plurality Figure 1 i 1 iew, in section, of the ore mediate shafts82, one end of each of W ice. red embodiment or my invention. Parts ofprov d wi h a l bearing suitably m l v are shown in elevation and partsare brokers n the h ft y a retaining w h h l by e m, ay to disclose theconstruction more clearly. screw 36, threaded into the end of the shaThe are 2 is sectional view taken in a plane outer race of each bearingis slidable as? his cated by the line 2-2 of Figure l. a circularaperture 3'2, which is formed.

ine 3 is a sectional view of a rnocliiled form wall 9 of the housin Acircula' plate 38 writing the intermediate gear. into the apertureserves to proverthe es oroad terms the transmission of myinvertlubricants the transmission eemprises a pair shafts, such asdrivingthe motor mechan r511 h ft cQZmecbsd by a plurality of Disposedadjacei one other of each. shaft is, and embodying means fo adjust- 32,is a second ball searing 39. whose outer race,

a @111. so that train is subjected to the same like that of the bearings33, is slidable axially in a torque. (line of the gear trains includesmeshed a circular aperture 41 formed in the web an M helical gears; andmeans provided for longlintermediate gear l2 having spiral teethnieslhhg tu ial adjustment, of one of these gears so that with those oithe driving gear 1'? is either pressed the resulting rotary movementeffects the desired or shrunk on each shaft 32 adjacent the hearing 59adjustment. Means are also provided for indi= 33; and an intermediatepinion cs, meshing with m5 eating" the desired alignmerit of the shafts.the ring gear '3, is preferably integrally formed. Tu greater detail,the transmission of my ii1- with the opposite end of each shaft adjacentthe aeration comprises a housing 2, having a flange 3, bearing 39. Asleeve is disposed on each shaft adapted to be secured by the bolts d,to the to maintain spaced elationship between gear or a motor or othermover a it cover ola From the above it will be clear that the driven anddriving shafts, are connected by two like gear trains, each of which, ifthe gears are in proper adjustment, carry an equal proportion of theload.

Means are provided for axially moving the, intermediate helical gearrelative to its meshed driving gear so that the resulting relativerotary movement can be utilized to adjust the gears by taking up alllost motion between them. To permit this axial movement without loss oftooth bearing surface, the gears 1'7 and 43 are longer than theirmeshing gears. The bearings 39 are adjustably secured in position in theweb 29 by oppositely disposed screws 46 arranged in pairs as best shownin Figure 2. The heads of the screws overlie the faces "of the outerrace of the bearing; the bearing being securely locked between the screwheads. By releasing the screws on one side and turning the oppositescrews, the

hearing may be shifted axially. The ends of the screws, exposed when thecover plate 7 is removed are provided with slots 48 to facilitate theirmanipulation.

One of the main causes of failure in transmission devices of thischaracter, 1. e., where the power transmitted is divided between aplurality of intermediate gear trains has been due to the extremedifficulty of securing proper adjustment of tooth pressure so that eachbranch of the intermediate gear trains carries an equal share of theload. It is obvious that this adjustment must be accurate within narrowlimits; otherwise the load is imposed on one branch alone, resultingultimately in undue wear and failure of the working parts.

The cost of production of a satisfactory device of this character hasheretofore been excessive due to the accuracy required in the machiningand assembly of the parts. Only a slight error, whether it be caused,for instance by a very small difference in the working depth of theteeth of two corresponding gears or by an angular difference in theregistration of the teeth of two intermediate shaft mounted gears, issuflicient to throw all of the transmitted load into one or the other ofthe intermediate gear trains with the result that this train soon fails.

All of these difficulties have been overcome in the transmission of myinvention by providing at least one of the intermediate gear trains withmeans whereby the torque may be equally divided between it and itscompanion mechanism. The angular registration of the teeth of the twointermediate shaft-mounted gears may be disregarded as any diiference inthe relationship between the teeth of corresponding gears in a train iscompensated for'by the proper setting up of the adjustable gear train.It follows from this that the precision methods of machining andassembly inherently necessary in non-adjustable devices of thischaracter may be dispensed with in the transmission of my invention; theonly accurate requirement in the present device being that thecenter-to-center distances of the various shafts and their axial andparallel alinement be reasonably accurate. Of course accurately cutgears are also required.

If the intermediate gear 42 be moved axially along the driving gear 17,a rotary movement will be imparted to the intermediate shaft by reasonof the teeth of the larger gear'sliding along those of the smaller gear.This rotary movement is utilized to advance or retard the teeth of theintermediate pinions 43 so that correct alinement is obtained betweenthem and those of the driven ring gear 23. Movement of the gear tosecure this adjustment is effected by shifting the bearings of either orboth of the shafts 32,

as already explained.

Means are provided for indicating when correct circumferential alinementof the gears obtains. During the process of cutting the teeth on theintermediate pinion a milling cutter is passed over the end of the gearso that a shoulder 49 is formed thereon. When the teeth in the drivengear is an even number, the shoulder 49 is located, in relation to atooth, identically in each of the gears produced.

It will be seen that the shoulders referred to play an important part inthe adjustment of the mechanism. Since the cover plate 'I and the drivengear 23 must necessarily be removed to permit access to the screws 46,it is obvious that without a visual indication of the correctcorrelation of the pinions and the absent gear, the adjustment of theparts would be more or less of an approximation rather than an accurateresult.

Knowing that the position of the shoulder, with reference to a tooth, isidentical on each pinion the mechanic need only assemble the gears sothat the shoulders on the gears are in linear alignment, which may beaccomplished by placing a straight-edge against both shoulders andmanipulating the screws 46 to bring the straightedge to a full seatthereon.

The heads of the screws 46 are provided with drilled holes 51 by meansof which the screw heads may be wired together and locked when the finaladjustment of the screws has been completed.

A modified form of mounting for the intermediate gear on the shaft 32,is shown in Figure 3. In this construction the gear 42, is slidablydisposed on the shaft; and is secured for rotation therewith by means ofthe key 52. Portions of the shaft are threaded to receive the adjustingnuts 53; and winged lock washers 54 are provided for locking the nutsagainst rotation when the correct adjustment of the gears has beenobtained. It is obvious that with the use of this type of intermediategear mounting; the screws 46 may be dispensed with and the bearings 33and 39 are fixed in the housing. Access to the adjusting nuts isobtained thru a suitable aperture in the housing normally covered by aplate 56.

The use of duplex or multiplex intermediate drives permits the use ofsmaller gears to give the same load carrying capacity, resulting in amore compact and smaller mechanism than is possible with a singly gearedtransmission. Transmissions of the character described have been builtand successfully operated under transmitted loads as high as 200horsepower; and have found particular usefulness in the driving of slowspeed pumps with high speed motors.

I claim:

1. A device of the character described, comprising'driving and drivenshafts, a helical gear on 140 one of the shafts, a gear on the other ofthe shafts,

a plurality of intermediate shafts, gears on each intermediate shaft andmeshing with the gears on the driving and driven shafts, a fixedelement,

a bearing for one of the intermediate shafts and 5 slidably disposed inthe fixed element, and a plurality of adjusting screws disposed betweenthe fixed element and the shaft bearing for axially adjusting theintermediate shaft.

2. In a device of the character described, a driv- 150 act-aces ingshaft, a driven shaft, a pinion having heiicai teeth secured to thedriving shaft, a gear fixed on the driven shaft, a plurality ofintermediate shafts, gears on the intermediate shafts and meshing withthe helical gear, pinions on each of the intermediate shafts and meshingwith the driven gear, a fixed element, a bearing for one of theintermediate shafts and slidahly disposed in the fixed element, and aplurality of adjusting screws disposed between the fixed element and theshaft bearing for axially adjusting the inter mediate shaft.

3. In a device of the character described, a driving shaft, a pinionsecured to the driving shaft and provided with helical teeth, a drivenshaft, a ring gear secured to the driven shaft, 9. pair of intermediateshafts, each intermediate shaft being provided at one end with a gearhaw.

ing helical teeth meshing with those of the driv= ing shaft pinion andat the other end with a pinion meshing with the ring gear, a housing forthe shafts, bearings on the intermediate shafts and slidably disposed inthe housing and a plurality oi screws threaded into the housing andhaving heads engaging the bearings for axially adjusting theintermediate shafts.

4.1111 a device of the character described, a driving shaft, a pinionsecured to the driving shaft and provided with helical teeth, a drivenshaft, a ring gear secured to the driven shaft, a pair of intermediateshafts, each intermediate shaft being provided at one end with a gearhaving helical teeth meshing with those of the driving shaft pinion andat the other end with a pinion meshing with the ring gear, a housing forthe shafts, hearings on the intermediate shafts and slidably disposed inthe housing, a plurality of screws threaded into the housing and havingheads engaging the bearings foraxiaiiy adjusting the intermediateshafts, and means on each of the intermediate shafts for indicatingcircumierentiai alinement of corresponding intermediate shaft pinioiis.

PHILIP L. BANNAN.

